The Duchess of Cambridge opted to honour a Polish designer with her choice of dress for the first day of their royal tour of the country.

The Duchess, who was accompanied by Prince William, looked incredible in a white knee-length cocktail dress by Gosia Baczynska for a garden party in Warsaw, Poland.

Celebrating the Queen’s birthday at the Orangery in Warsaw’s Lazienki Park, the Duchess paired her outfit with a beautiful pearl necklace and matching earrings, a small black clutch and a pair of simple black heels.

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Prince William, Duke of Cambridge and Catherine, Duchess of Cambridge prepare to toast HM The Queen at the Queen's Birthday Garden Party at the Orangery, Lazienki Park on day 1 of their official visit to Poland on July 17, 2017 in Warsaw, Poland.

The Duke and Duchess are on a five-day tour of Germany and Poland.

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Prince William, Duke of Cambridge, Catherine, Duchess of Cambridge and Poland's First Lady Agata Kornhauser-Duda attend the Queen's Birthday Garden Party at the Orangery, Lazienki Park on day one of their official visit to Poland on 17 July 2017 in Warsaw, Poland.

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Prince William, Duke of Cambridge, Catherine, Duchess of Cambridge and Poland's First Lady Agata Kornhauser-Duda attend the Queen's Birthday Garden Party at the Orangery, Lazienki Park on day 1 of their official visit to Poland on July 17, 2017 in Warsaw, Poland.

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Duchess of Cambridge listens as Prince William, Duke of Cambridge gives a speech during the Queen's Birthday Garden Party at the Orangery on day 1 of their official visit to Poland on July 17, 2017 in Warsaw, Poland.

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Prince William, Duke of Cambridge and Catherine, Duchess of Cambridge prepare to toast HM The Queen at the Queen's Birthday Garden Party at the Orangery, Lazienki Park on day 1 of their official visit to Poland on July 17, 2017 in Warsaw, Poland.

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Prince William, Duke of Cambridge and Catherine, Duchess of Cambridge attend the Queen's Birthday Garden Party at the Orangery, Lazienki Park on day 1 of their official visit to Poland on July 17, 2017 in Warsaw, Poland.